Legionella have been known for some time to live within amoebae in the natural environment and members of the genus Francisella. Legionella species are the causative agent of the human Legionnaires' disease and the lesser form, Pontiac fever. Legionella transmission is via aerosols—the inhalation of mist droplets containing the bacteria. Common sources include cooling towers, domestic hot-water systems, fountains, and similar disseminators that tap into a public water supply

Recent research in the Journal of Infectious Diseases provides evidence that Legionella pneumophila, the causative agent of Legionnaires disease, can travel at least 6 km from its source by airborne spread.

Infections of Protozoa: Protozoa such as Harmanella vermiformis and related protozoa have been shown to be able to support the growth of L. pneumophila in tap water. Also Acanthamoeba, Naegleria and Tetrahymena can be infected by L. pneumophila. This pathway may be how these organisms survive in the environment.http://encyclopedia.thefreedictionary.com/Legionella

Legionella: L. pneumophila is the bacterium associated with Legionnaires' disease and Pontiac fever. Patients can develop severe pneumonia which is not responsive to penicillins or aminoglycosides. Legionnaires' disease also has the potential to spread into other organ-systems of the body such as the gastrointestinal tract and the central nervous system. L. micdadei is the second most commonly isolated member of Legionella. This bacterium can cause the same flu-like symptoms and pneomonia which characterize an L. pneumophila infection

Necrotizing cellulitis caused by Legionella micdadei.Legionella micdadei is primarily considered a pathogen of the pulmonary tract of immunocompromised p...www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1731498&dopt=Abstract - Similar pages

Legionella pneumophila immunity and immunomodulation: nature and ...In addition, interleukins, such as interleukin 1 and 2, as well as interferon and tumor necrotizing factor, appear in response to Legionella antigens and ...www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3059772&dopt=Abstract - Similar pages[ More results from www.ncbi.nlm.nih.gov ]

A bacterium from the Legionella family, not previously associated with human disease, has been identified as the cause of pneumonia in a woman in France. Researchers from the Hopital Paul Brousse in Villejuif, France, report this first case in the July 1997 issue of the Journal of Clinical Microbiology.

The researchers report on a 34-year-old woman who, 4 weeks after a liver transplant, developed severe pneumonia. She suffered neurological deterioration and eventually went into a coma. After several weeks of various antibiotic treatments and a second liver transplant, she recovered.

The cause of her pneumonia was found to be the bacterium Legionella parisiensis. This bacterium was first identified in a cooling tower in Paris in 1985 and since then no further isolations of this organism have been reported until this case. The family Legionellaceae comprises 42 species among which 18 have been isolated from patients with pneumonia. The most well known species is Legionella pneumophila, the cause of Legionnaire's disease, which accounts for nearly 90% of Legionella infections.(F.L. Presti, S. Riffard, F. Vandenesch, M. Reyrolle, E. Ronco, P. Ichai, and J. Etienne. 1997. The first clinical isolate of Legionella parisiensis from a liver transplant patient with pneumonia. Journal of Clinical Microbiology. 35:1706-1709.)http://www.q-net.net.au/~legion/Legionnaires_Disease_Odds_and_Sods.htm